Grinding wheel



Sept. 16, 1941. Q W 2,256,367

GRINDING WHEEL Filed May 16, 1939 2 SheetsSheet 1 INVENTOR Carl m1;

ATTORN EY C. WOLF GRINDING WHEEL Filed Ma 16, 1939 2 Sheets-Sheet 2INVENTOR Carl Wolf:

ATTORN EY Sept. 16-, 1941.

Patented Sept. 16, 1941 GRINDING WHEEL Carl Wolf, Meriden, Conn.Application May 16, 1939, Serial No. 273,901

7 Claims.

This invention relates to grinding wheels, and more particularly to animproved reinforcing means for an annular grinding wheel constructed ofplastic abrasive compound, and having an organic binder, such asshellac, silicate, rubber or Bakelite.

Grinding wheels of the above nature are usually made from 6 to 24 inchesin diameter, and are often operated at surface speeds higher than 5000feet per minute so that unless reinforced, said grinding wheels wouldfly apart, due to the excessive stresses developed at such speeds.

One object of the present invention is to provide an inexpensivereinforcing means for a grinding wheel of the above nature in which thepossibility of fractures will be reduced to a minimum.

Another object is to provide a reinforcing means of the above naturewhich is adapted to be embedded in the wheel during the molding thereof.

A still further object is to provide a reinforced grinding wheel of theabove nature which will be simple in construction, relativelyinexpensive to manufacture, easy to manipulate, compact, ornamental inappearance, and very efiicient and durable in use.

With these and other objects in view, which will appear as thedescription proceeds, there have been illustrated in the accompanyingdrawings, several forms in which the invention ma; be convenientlyembodied in practice.

In the drawings:

Fig. 1 is a rear end face view of a cylindrical grinding wheel embodyingthe features and principles of this invention, and showing one form ofreinforcing means.

Fig. 2 is a sectional view taken on the line 2-2 of Fig. 1.

Fig. 3 is a rear end face view of a grinding Wheel having a modifiedform of reinforcing means.

Fig. 4 is a sectional view 4-4 of Fig. 3.

Fig. 5 is a fragmentary end view of another modified form of reinforcingmeans, shown separately from the grinding wheel.

Fig. 6 is a sectional view taken on the line E6 of Fig. 5.

Fig. 7 is a side view, partly in section, of an apparatus employed formolding a grinding wheel with the first form of reinforcing meansembedded therein.

Fig. 8 is a side view, partly in section, showing taken on the line theappearance of the first form of grinding wheel when attached directly tothe face of a driving spindle.

Referring now to the drawings wherein like reference numerals designatelike parts throughout the several Views, the numeral Ill denotes anannular or ring-shaped grinding wheel formed by high-pressure moldingfrom any suitable plastic abrasive compound having an organic binder. Amold suitable for use in molding a grinding wheel of the above nature isshown in Fig. 7, and includes a bottom plate ll, an outer side ring l2and a central cylindrical core I3. The molding apparatus is adapted tobesecured to a face plate I4 of a driving spindle hub l5, by means of amold cover plate l6 secured to said plate M by headed screws [1. Thecore [3 is of the proper size to correspond with the height of thegrinding wheel being molded, and the abrasive material is compressedtightly within the outer ring I2 and between the mold bottom II and thecover plate I6. A narrow wheel centering hub I8 is preferably providedon the plate IE to form a recess I9 in the resulting grinding wheel l0.

Each of the three forms of reinforcing means shown in the drawings isadapted to be secured against the face of the cover plate l6 within themold, by screws 20, which are relatively longer than the screws 1! whichpass through the face plate l4 and which are adapted to be driven into apluralityof sleeve-like nuts 2|, three in this instance. The nuts 2| arepreferably roughened on their outer periphery, such as by knurling. Inthe form shown in Figs. 1 and 2, the nuts 2! are secured, as byspot-welding, to the points 23 on the inside of a flat circular Wire ormetal strip 22, although said nuts may be secured to the outside of saidstrip if desired. The flat metal Wire 22 is preferably roughened,corrugated or serrated on its inner and outer flat surfaces and edges toinsure that the abrasive material will more efiiciently adhere thereto.

After being molded, the grinding wheel It] will be removed from the moldand may, if desired, be used with the face plate l4 secured to the coverplate l6, as shown in Fig. 7, or the cover plate l6 may be removed fromthe assembly and the Wheel l0 secured to a face plate 24, see Fig. 8,provided with a centering hub 25, by means of screws 26a threaded intothe knurled nuts 2|.

When grinding wheels of larger size are to be molded, the reinforcingmeans will preferably include an additional ring 26 of fiat metallicwire or strip material spot welded at 2! inside of the knurled nuts 2|(see Figs. 3 and 4).

to the A further modified form of the invention is shown in Figs. and 6,wherein a looped U- shaped strap 28 is disposed to overlie and embraceeach of the nuts 2| with the foot ends of said straps spot-welded at 29to the flat wire ring 22.

In all instances, the nuts 2| and the rings 22 and 28 are disposed flushwith. the rear face of the grinding wheel II! and are embedded in theinterior thereof. By means of this construction, a very eificient anddurable reinforcing means for the grinding wheel I0 is provided, whichmay safely be used at very high operating speeds and for heavy grindingwork. It will be understood that the word welding as employed in thisapplication, includes any method of securing the anchoring lugs to thering member with or without the use of high temperature and pressure.

While there have been disclosed in this specification several forms inwhich the invention may be embodied, it is to be understood that theseforms are shown for the purpose of illustration only, and that theinvention is not to be limited to the specific disclosures but may bemodified and embodied in various other forms Without departing from itsspirit. In short, the invention includes all the modifications :andembodiments coming within the scope of the following claims.

Having thus fully described the invention, what is claimed as new andfor'which it is desired to secure Letters Patent, is:

1. In a grinding Wheel of molded abrasive material and having a' flatrear face, reinforcing means including a plurality of nuts spaced apartabout the wheel, and a ring of fiat strip metal surrounding said nutsand spot-welded thereto, said nuts and ring being disposed with theirendsand edge respectively flush with the rear end face of said wheel andembedded in the abrasive material of said wheel.

2. In a grinding wheel of molded abrasive material and having a flatrear face, reinforcing means including a plurality of nuts embedded insaid wheel flush with the rear end thereof, and a ring of flat stripmetal spot-welded to each of said nuts and also embedded in the abrasivematerial of said wheel, a face plate abutted against the rear end ofsaid wheel, and screws passing through said plate and screw threadedinto said nuts to secure said wheel to said plate.

3. In a grinding wheel of molded abrasive material and having a flatrear face, reinforcing means including a plurality of nuts spaced apartabout said wheel, a ring of flat strip metal spotwelded to the outerside of each of said nuts, and a second ring of flat strip metalspot-welded to the inner side of saidnuts, said nuts and rings beingembedded as a unit in the abrasive material of said wheel flush with therear end face thereof.

4. In a grinding disk constructed of molded abrasive material and havinga flat rear face, a reinforcing and attaching means comprising aplurality of nuts embedded in the back of said wheel and a metal ringsurrounding said nuts and welded thereto also embedded in the back ofsaid wheel.

5. A grinding wheel of the class described comprising in combination, arotatable support having bolts extending away therefrom in the samedirection and in spaced relation, a unitary annulusof abrasive material,a ring member of rigid material embedded in said annulus, and nutswelded to saidring'member at spaced points therearound, said nuts beingadapted to receive said bolts.

6. In a grinding wheel constructed of molded abrasive material havinga-flat rear face, reinforcing means-including a ring member of rigidmaterial and aplurality of anchoring devices metallurgically secureddirectly thereto at spaced intervals around the periphery thereof, saidring member and anchoring device being embedded in the material of saidwheel during molding.

7. In a grinding wheel constructed of molded abrasive material havingaflat rear face; a reinforcing means including a ring member of rigidmaterial and a plurality of anchoring lllg mem- V bers m'etallurgicallysecured directly thereto at spaced intervals around the peripherythereof, said ring member and anchoring lug members being embedded inthe material of said wheel during molding.

CARL WOLF.

